Remote control electrical circuit

ABSTRACT

The invention disclosed involves an electrical control circuit wherein a relatively low voltage is used to control a relatively high voltage and includes switching means in the low voltage circuit and means responsive to said switching means for generating a low voltage pulse upon closing said switch, and switching means in the high voltage circuit responsive to the low voltage pulse to become conductive.

[451 Sept. 25, 1973 1 REMOTE CONTROL ELECTRICAL CIRCUIT [75] Inventors:Andrew F. Kay, Del Mar; Sam

Messin, Solana Beach, both of Calif.

[73] Assignee: Switchpack Systems, Inc., Solana Beach, Calif.

[22] Filed: Sept. 27, 1971 21 Appl-.No,:'l 83,842

Swinehart 317/1485 B Squires 317/1485 B Primary ExaminerRobert K.Schaefer Assistant Examiner-William J. Smith Artorney Edgar H. Kent 57-ABSTRACT The invention disclosed involves an electrical control [52] Q-307/252. circuit wherein a relatively low voltage is used to cong Y317/1485 B trol a relatively high voltage and includes switching [51]Ilit. Cl. "01h 47/32- means in the low voltage Circuit and meansresponsive [-58] held of Search" 307/140 1 106; i to said switchingmeans for generating a low voltage 17 4 B pulse upon closing saidswitch, and switching meansin v 1 the high voltage circuit responsive tothe low voltage [56] R pulse to become conductive.

UNITED STATES PATENTS 3,527,957 9/l970 Eck 307/!40 7 Claims, 5 DrawingFigures x IO o I r Q PATENTEDSEPZSW 3.781.738

' Z INVENTOR. ANDREW F. KAY

BY SAM (NMHMESSIN PATENTED SEPZ 5 I975 sum 2 OF 2 PIC-3.5

INVENTOR.

ANDREW F. KAY

BY M (NM!) MESSIN REMOTE CONTROL ELECTRICAL CIRCUIT Our inventionrelates to a remote control switching electrical circuit. It isparticularly applicable to low voltage switching controls for domesticand commercial use wherein a relatively low voltage and current can beused for controlling relatively high voltage and- /or heavy currentelectrical circuits.

The electrical industry has heretofore used a low voltage push buttonfor energizing a solenoid to control a switch in. a relatively highvoltage circuit such as incandescent lights in lighting circuits.'Suchcircuits have usually taken the form of a source of low voltage such asfrom a step-down, transformer, a solenoid coil connected to said sourceof low voltage and a push button switch interposed in series between thesecondary of the step-down transformer and the solenoid. The solenoidmechanically actuates an on-of switch in series in the high voltagecircuit.

There are several obvious disadvantages to such circuits, one of theprimary being that in the event the push button is inadvertantlydepressed and held in the depressed condition electricity will continueto flow through the solenoid coil and will tend to overheat or damagethe coil.

One of the primary objects of our invention is to provide a remotecontrol system, which uponclosing the remote control switch button,generates a pulse for the operation of the remote solenoid, but will notcontinue to energize the solenoid even though the push button switchremains closed.

A further disadvantage of the heretofore known remote control circuitslies in the fact that the current in the remote control switch must belarge enough and of sufficiently high voltage to operate the solenoid. Afurther advantage of our system lies in the fact that a much lowervoltage and extremely low current can be used at the point of remotecontrol than has heretofore been possible.

Other objects and advantages will become apparent from the drawings andspecifications descriptive thereof.

In the drawings:

' FIG. 1 is a schematic representation of an electrical circuitadaptable for use in our invention.

FIG. 2 is a sine wave representing the alternating current input intothe control circuit.

FIG. 3 is a distorted sine wave representing the form of the current atan intermediate point in the control circuit.

FIG. 4 is a representation of the pulse which actuates the solenoid.

FIG. 5 is a modified form of control circuit embodying the principles ofour invention.

Referring to FIG. 1, we have provided a high voltage circuit comprisingconductors and 11. It will be understood that the term high voltage" isrelative to distinguish it from the-relatively lower voltage control circuits. Normally in an incandescent lighting circuit the high voltagecircuit would be 110 volts.

The first control circuit comprises a step-down transformer T-l havingits primary coil 12 connected across the conductors 10 and 11.

In the event that it is desired to further reduce the voltage or reducethe power across the primary coil 12 a resistor 13 may be provided inseries with said coil 12.

The step-down transformer T-l is provided with a secondary or outputcoil 15 having terminals 16 and 17. The output circuit of thetransformer T-ll comprises a circuit having a normally open push buttonswitch 18, a rectifier 19, a capacitor 20 and an isolating transformerT-2 through primary coil 21 and terminals 22 and 23. A resistor 24 isconnected in shunt across the capacitor 20 and isolating transformerT-2.

Isolating transformer T-2 has secondary coil 26 having output terminals27 and 28. The output terminals 27 and 28 of coil 26 are connected to anelectronic gate or electrical valve such as triac 30.

A solenoid coil31 is connected in series with the gate 30 across thehigh voltagelines 10 and 11 by means of conductors 32, 33 and 34.

The solenoid 31 is mechanically connected to an electromechanicalswitching device such as 35, preferably of a ratchet type so that eachpulse, or actuation of the solenoid 31 will actuate the switchingmechanism to successively make or break the electrical connectionbetween the high voltage line 10 and the switch output terminal 36. Itwill be understood that the electrical device being energized orcontrolled by means of the switching device 35 will be connected acrossthe terminals 36 and 37.

In the operation of the circuit an alternating current of relativelyhigh potential is applied across the terminals l0 and 11. The highpotential current has a sine wave form such as illustrated in FIG. 2.The resistor 13 performs a dual function in that it reduces the voltageacross the primary coil 12 and also distorts the wave form to accentuatethe peak of each alternating pulse such as in FIG. 3.

Upon closing the switch 18 the secondary circuit of the transformer T-lis completed, wherein half-wave pulses which are permitted to passrectifier l9 charge capacitor 20. While capacitor 20 is being charged,current flows through coil I211 thereby inducing a series of pulses fromcoil 26.

In view of the fact that the first half wave cycle from coil 15 whichpasses through rectifier 19 substantially fully charges capacitor 20,the first half-wave pulse results in a relatively large pulse from thesecondary coil 26 which is sufficiently large to turn on the gate 30.Because of the charged condition of capacitor 20, each successivehalf-wave through the rectifier 19 results in a successively diminishingpulse from coil 26 such as illustrated in FIG. 4.

Upon activating the gate 30, sufficient current flows through thesolenoid 31 to activate the switch 35 to its next stage of either on oroff.

It will be readily apparent that-once capacitor 20 is fully charged, itwill make no difference how long switch 18 is held closed, because nofurther substantial current can flow through coil 26 to actuate gate 30to a conductive state; therefore current will not continue to flowthrough solenoid coil 31.

Upon opening switch 18 capacitor 20 will be discharged through resistor24. Resistor 24, of course, will be of sufficient resistance to preventan excessively fast discharge of capacitor 201.

We have illustrated our invention in its broadest concept, that is, as aremote control electrical system. The primary objective is for a lowvoltage control of light circuits and other applicances in domestic andindustrial uses by means of what is commonly known as a touch-platesystem. It will be readily apparent that the switch 18 can assume theform ofa switch plate or pressure responsive switch which is adapted toactuate the solenoid switch 35 by being touched or pushedflt will befurther apparent that we have eliminated one of the primary problems inconnection with heretofore known touch-plate systems, in that,regardless of how long a user keeps switch 18 closed, there is no dangerthat the solenoid coil can overheat.

We have also devised and provided a system of remote control wherein thecurrent and voltage used in the remote station may be extremely smallcompared even with the voltage required to actuate the electromechanicalswitching means.

FIG. 5 illustrates a modified form of a control circuit. Similar numbersin FIGS. 5 and 1 are intended to indicate similar parts. In thismodification there is also a source of high voltage and 11.

A resistor 40and Zener diode 41 are connected in series across thesource of high voltage 10 and 11 to thereby generate a low voltagesquare wave form across the Zener diode.

A capacitor 42 is connected in series with resistor 43, control switch44 and resistor 45 in shunt across the Zener diode 41.

The capacitor 42 differentiates the square wave form from the Zenerdiode 41 into sharp pips, such as 47, at the front and trailing edge ofthe square wave form.

A diode 49 is connected to the high voltage source 10 through resistor40 and to collector 51 through resistor 50 and to high voltage source 11through capacitor 52. The diode 49, resistor 50 and capacitor 52 form ahalf wave power supply for transistor T-3.

Capacitor 42 is connected to the base 55 of transistor T-3 in serieswith diode 56. The emitter of transistor T-3 is also connected to thesource of high voltage 11 through resistor 54 and to the'electronicgate, or triac 30 through diode 57.

In the operation of the modified circuit, resistor 40 limits the voltageacross the Zener diode 41 to any desired low voltage, and generates asquare wave form potential, which, together with capacitor 42 producessharp pulses such as 47 at the leading and trailing edge of the squarewave form. Diode 49, resistor 50 and capacitor 52 form a half wave powersupply.

In the normal state capacitor 42 remains charged and no current flowsuntil resistors 43 and 45 are connected in a return path by means ofswitch 44. When the return path is complete, positive pulses triggertransistor T-3 through diode 56.

When transistor T-3 is triggered to on" or conductive condition,capacitor 52 discharges through transistor T-3, most of the dischargeoccuring on the first pulse. So long as switch 44 remains closed, nofurther charge of capacitor 42 is possible.

The discharge through transistor T-3 and resistor 54 produces a pulseacross resistor 54 which is coupled through diode 57 to the gate ortriac 30, triggering the triac, or electronic gate to on condition.

Since the pulses originate synchronically from the high voltage linefrequency, the trigger pulse at the triac gate 30 is occuring at thesame time the line voltage is increasing at the triac anode. The gate 30(or triac) turns on for the duration of the half-cycle of the A-C powerthereby actuating the solenoid to turn the switch to on or offpositions. Maximum pulse amplitude occurs upon discharge of capacitor 52coincident with the first pulse from transistor T-3. The time constantof resistor 50 and capacitor 52 is such that capacitor 52 cannot chargesufficiently between pulses to sustain 5 constant triggering of the gateof-triac 30.

Whereas we have described our invention in one of its more practicalembodiments it will be understood that our invention is not limited tothe specific configuration shown herein, but is more clearly delineatedin the appended claims.

I claim:

1. An electrical circuit adapted to actuate relatively high voltageelectrical switching means comprising:

electronic switching means in series with said high voltage electricalswitching means for operatively connecting the same to a source of highvoltage current, said electronic switching means being of a type whichis rendered conductive of the high voltage current to actuate said highvoltage electrical switching means only by a control pulse of sufficientmagnitude applied thereto and which is maintained in said conductivestate only by applying further such pulses thereto; a relatively lowvoltage control circuit including control switching means; and

pulsing means rendered operative at one condition of said controlswitching means for providing to said electronic switching means onlyone control pulse of said magnitude while said control switching meansis maintained in said one condition.

2. An electrical circuit according to claim 1 wherein said high voltageelectrical switching means is arranged to make and break a circuit onsuccessive actuations thereof.

3. An electrical circuit according to claim 2 wherein said pulsing meansis connected to provide said control pulse during a half cycle of analternating current.

4. An electrical circuit according to claim 3 wherein said high voltageelectric switching means, said electronic switching meansand saidcontrol circuit are connected across the same source of high voltagealternating current and said control circuit includes voltage reducingmeans and rectifying means.

5. An electrical circuit according to claim 4 wherein said high voltageswitching means is a ratchet type solenoid switch.

6. An electrical circuit according to claim 1 wherein said pulsing meansis arranged to provide a series of pulses to said electronic switchingmeans only the first of which is of said magnitude.

7. An electrical circuit according to claim 1 wherein said pulsing meansincludes a transistor having its emitter electrode connected to providepulses to said electronic switching means, circuitry connected betweenthe base of the transistor and said control switching meansfor renderingsaid transistor conductive only while said control switching means is insaid one position, a capacitor connected to the collector of thetransistor to be discharged when the transistor is rendered conductive,and circuit means connected to said consenser to fully charge the sameonly when the transistor is non-conducting.

* i l 0 i

1. An electrical circuit adapted to actuate relatively high voltageelectrical switching means comprising: electronic switching means inseries with said high voltage electrical switching means for operativelyconnecting the same to a source of high voltage current, said electronicswitching means being of a type which is rendered conductive of the highvoltage current to actuate said high voltage electrical switching meansonly by a control pulse of sufficient magnitude applied thereto andwhich is maintained in said conductive state only by applying furthersuch pulSes thereto; a relatively low voltage control circuit includingcontrol switching means; and pulsing means rendered operative at onecondition of said control switching means for providing to saidelectronic switching means only one control pulse of said magnitudewhile said control switching means is maintained in said one condition.2. An electrical circuit according to claim 1 wherein said high voltageelectrical switching means is arranged to make and break a circuit onsuccessive actuations thereof.
 3. An electrical circuit according toclaim 2 wherein said pulsing means is connected to provide said controlpulse during a half cycle of an alternating current.
 4. An electricalcircuit according to claim 3 wherein said high voltage electricswitching means, said electronic switching means and said controlcircuit are connected across the same source of high voltage alternatingcurrent and said control circuit includes voltage reducing means andrectifying means.
 5. An electrical circuit according to claim 4 whereinsaid high voltage switching means is a ratchet type solenoid switch. 6.An electrical circuit according to claim 1 wherein said pulsing means isarranged to provide a series of pulses to said electronic switchingmeans only the first of which is of said magnitude.
 7. An electricalcircuit according to claim 1 wherein said pulsing means includes atransistor having its emitter electrode connected to provide pulses tosaid electronic switching means, circuitry connected between the base ofthe transistor and said control switching means for rendering saidtransistor conductive only while said control switching means is in saidone position, a capacitor connected to the collector of the transistorto be discharged when the transistor is rendered conductive, and circuitmeans connected to said consenser to fully charge the same only when thetransistor is non-conducting.